Update and document memory barriers for mqueue.c:
- ewp->state is read without any locks, thus READ_ONCE is required.
- add smp_aquire__after_ctrl_dep() after the READ_ONCE, we need
acquire semantics if the value is STATE_READY.
- use wake_q_add_safe()
- document why __set_current_state() may be used:
Reading task->state cannot happen before the wake_q_add() call,
which happens while holding info->lock. Thus the spin_unlock()
is the RELEASE, and the spin_lock() is the ACQUIRE.
For completeness: there is also a 3 CPU scenario, if the to be woken
up task is already on another wake_q.
Then:
- CPU1: spin_unlock() of the task that goes to sleep is the RELEASE
- CPU2: the spin_lock() of the waker is the ACQUIRE
- CPU2: smp_mb__before_atomic inside wake_q_add() is the RELEASE
- CPU3: smp_mb__after_spinlock() inside try_to_wake_up() is the ACQUIRE
Link: http://lkml.kernel.org/r/20191020123305.14715-4-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Waiman Long <longman@redhat.com>
Cc: <1vier1@web.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Null pointers were assigned to local variables in a few cases as exception
handling. The jump target “out” was used where no meaningful data
processing actions should eventually be performed by branches of an if
statement then. Use an additional jump target for calling dev_kfree_skb()
directly.
Return also directly after error conditions were detected when no extra
clean-up is needed by this function implementation.
Link: http://lkml.kernel.org/r/592ef10e-0b69-72d0-9789-fc48f638fdfd@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dev_kfree_skb() input parameter validation, thus the test around the call
is not needed.
This issue was detected by using the Coccinelle software.
Link: http://lkml.kernel.org/r/07477187-63e5-cc80-34c1-32dd16b38e12@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs mount updates from Al Viro:
"The first part of mount updates.
Convert filesystems to use the new mount API"
* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
mnt_init(): call shmem_init() unconditionally
constify ksys_mount() string arguments
don't bother with registering rootfs
init_rootfs(): don't bother with init_ramfs_fs()
vfs: Convert smackfs to use the new mount API
vfs: Convert selinuxfs to use the new mount API
vfs: Convert securityfs to use the new mount API
vfs: Convert apparmorfs to use the new mount API
vfs: Convert openpromfs to use the new mount API
vfs: Convert xenfs to use the new mount API
vfs: Convert gadgetfs to use the new mount API
vfs: Convert oprofilefs to use the new mount API
vfs: Convert ibmasmfs to use the new mount API
vfs: Convert qib_fs/ipathfs to use the new mount API
vfs: Convert efivarfs to use the new mount API
vfs: Convert configfs to use the new mount API
vfs: Convert binfmt_misc to use the new mount API
convenience helper: get_tree_single()
convenience helper get_tree_nodev()
vfs: Kill sget_userns()
...
Andreas Christoforou reported:
UBSAN: Undefined behaviour in ipc/mqueue.c:414:49 signed integer overflow:
9 * 2305843009213693951 cannot be represented in type 'long int'
...
Call Trace:
mqueue_evict_inode+0x8e7/0xa10 ipc/mqueue.c:414
evict+0x472/0x8c0 fs/inode.c:558
iput_final fs/inode.c:1547 [inline]
iput+0x51d/0x8c0 fs/inode.c:1573
mqueue_get_inode+0x8eb/0x1070 ipc/mqueue.c:320
mqueue_create_attr+0x198/0x440 ipc/mqueue.c:459
vfs_mkobj+0x39e/0x580 fs/namei.c:2892
prepare_open ipc/mqueue.c:731 [inline]
do_mq_open+0x6da/0x8e0 ipc/mqueue.c:771
Which could be triggered by:
struct mq_attr attr = {
.mq_flags = 0,
.mq_maxmsg = 9,
.mq_msgsize = 0x1fffffffffffffff,
.mq_curmsgs = 0,
};
if (mq_open("/testing", 0x40, 3, &attr) == (mqd_t) -1)
perror("mq_open");
mqueue_get_inode() was correctly rejecting the giant mq_msgsize, and
preparing to return -EINVAL. During the cleanup, it calls
mqueue_evict_inode() which performed resource usage tracking math for
updating "user", before checking if there was a valid "user" at all
(which would indicate that the calculations would be sane). Instead,
delay this check to after seeing a valid "user".
The overflow was real, but the results went unused, so while the flaw is
harmless, it's noisy for kernel fuzzers, so just fix it by moving the
calculation under the non-NULL "user" where it actually gets used.
Link: http://lkml.kernel.org/r/201906072207.ECB65450@keescook
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Andreas Christoforou <andreaschristofo@gmail.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Our msg priorities became an rbtree as of d6629859b3 ("ipc/mqueue:
improve performance of send/recv"). However, consuming a msg in
msg_get() remains logarithmic (still being better than the case before
of course). By applying well known techniques to cache pointers we can
have the node with the highest priority in O(1), which is specially nice
for the rt cases. Furthermore, some callers can call msg_get() in a
loop.
A new msg_tree_erase() helper is also added to encapsulate the tree
removal and node_cache game. Passes ltp mq testcases.
Link: http://lkml.kernel.org/r/20190321190216.1719-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We already store the current task fo the new waiter before calling
wq_sleep() in both send and recv paths. Trivially remove the redundant
assignment.
Link: http://lkml.kernel.org/r/20190321190216.1719-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs mount infrastructure updates from Al Viro:
"The rest of core infrastructure; no new syscalls in that pile, but the
old parts are switched to new infrastructure. At that point
conversions of individual filesystems can happen independently; some
are done here (afs, cgroup, procfs, etc.), there's also a large series
outside of that pile dealing with NFS (quite a bit of option-parsing
stuff is getting used there - it's one of the most convoluted
filesystems in terms of mount-related logics), but NFS bits are the
next cycle fodder.
It got seriously simplified since the last cycle; documentation is
probably the weakest bit at the moment - I considered dropping the
commit introducing Documentation/filesystems/mount_api.txt (cutting
the size increase by quarter ;-), but decided that it would be better
to fix it up after -rc1 instead.
That pile allows to do followup work in independent branches, which
should make life much easier for the next cycle. fs/super.c size
increase is unpleasant; there's a followup series that allows to
shrink it considerably, but I decided to leave that until the next
cycle"
* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
afs: Use fs_context to pass parameters over automount
afs: Add fs_context support
vfs: Add some logging to the core users of the fs_context log
vfs: Implement logging through fs_context
vfs: Provide documentation for new mount API
vfs: Remove kern_mount_data()
hugetlbfs: Convert to fs_context
cpuset: Use fs_context
kernfs, sysfs, cgroup, intel_rdt: Support fs_context
cgroup: store a reference to cgroup_ns into cgroup_fs_context
cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper
cgroup_do_mount(): massage calling conventions
cgroup: stash cgroup_root reference into cgroup_fs_context
cgroup2: switch to option-by-option parsing
cgroup1: switch to option-by-option parsing
cgroup: take options parsing into ->parse_monolithic()
cgroup: fold cgroup1_mount() into cgroup1_get_tree()
cgroup: start switching to fs_context
ipc: Convert mqueue fs to fs_context
proc: Add fs_context support to procfs
...
Convert the mqueue filesystem to use the filesystem context stuff.
Notes:
(1) The relevant ipc namespace is selected in when the context is
initialised (and it defaults to the current task's ipc namespace).
The caller can override this before calling vfs_get_tree().
(2) Rather than simply calling kern_mount_data(), mq_init_ns() and
mq_internal_mount() create a context, adjust it and then do the rest
of the mount procedure.
(3) The lazy mqueue mounting on creation of a new namespace is retained
from a previous patch, but the avoidance of sget() if no superblock
yet exists is reverted and the superblock is again keyed on the
namespace pointer.
Yes, there was a performance gain in not searching the superblock
hash, but it's only paid once per ipc namespace - and only if someone
uses mqueue within that namespace, so I'm not sure it's worth it,
especially as calling sget() allows avoidance of recursion.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A lot of system calls that pass a time_t somewhere have an implementation
using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have
been reworked so that this implementation can now be used on 32-bit
architectures as well.
The missing step is to redefine them using the regular SYSCALL_DEFINEx()
to get them out of the compat namespace and make it possible to build them
on 32-bit architectures.
Any system call that ends in 'time' gets a '32' suffix on its name for
that version, while the others get a '_time32' suffix, to distinguish
them from the normal version, which takes a 64-bit time argument in the
future.
In this step, only 64-bit architectures are changed, doing this rename
first lets us avoid touching the 32-bit architectures twice.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull timekeeping updates from Thomas Gleixner:
"The timers and timekeeping departement provides:
- Another large y2038 update with further preparations for providing
the y2038 safe timespecs closer to the syscalls.
- An overhaul of the SHCMT clocksource driver
- SPDX license identifier updates
- Small cleanups and fixes all over the place"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
tick/sched : Remove redundant cpu_online() check
clocksource/drivers/dw_apb: Add reset control
clocksource: Remove obsolete CLOCKSOURCE_OF_DECLARE
clocksource/drivers: Unify the names to timer-* format
clocksource/drivers/sh_cmt: Add R-Car gen3 support
dt-bindings: timer: renesas: cmt: document R-Car gen3 support
clocksource/drivers/sh_cmt: Properly line-wrap sh_cmt_of_table[] initializer
clocksource/drivers/sh_cmt: Fix clocksource width for 32-bit machines
clocksource/drivers/sh_cmt: Fixup for 64-bit machines
clocksource/drivers/sh_tmu: Convert to SPDX identifiers
clocksource/drivers/sh_mtu2: Convert to SPDX identifiers
clocksource/drivers/sh_cmt: Convert to SPDX identifiers
clocksource/drivers/renesas-ostm: Convert to SPDX identifiers
clocksource: Convert to using %pOFn instead of device_node.name
tick/broadcast: Remove redundant check
RISC-V: Request newstat syscalls
y2038: signal: Change rt_sigtimedwait to use __kernel_timespec
y2038: socket: Change recvmmsg to use __kernel_timespec
y2038: sched: Change sched_rr_get_interval to use __kernel_timespec
y2038: utimes: Rework #ifdef guards for compat syscalls
...
Linus recently observed that if we did not worry about the padding
member in struct siginfo it is only about 48 bytes, and 48 bytes is
much nicer than 128 bytes for allocating on the stack and copying
around in the kernel.
The obvious thing of only adding the padding when userspace is
including siginfo.h won't work as there are sigframe definitions in
the kernel that embed struct siginfo.
So split siginfo in two; kernel_siginfo and siginfo. Keeping the
traditional name for the userspace definition. While the version that
is used internally to the kernel and ultimately will not be padded to
128 bytes is called kernel_siginfo.
The definition of struct kernel_siginfo I have put in include/signal_types.h
A set of buildtime checks has been added to verify the two structures have
the same field offsets.
To make it easy to verify the change kernel_siginfo retains the same
size as siginfo. The reduction in size comes in a following change.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Christoph Hellwig suggested a slightly different path for handling
backwards compatibility with the 32-bit time_t based system calls:
Rather than simply reusing the compat_sys_* entry points on 32-bit
architectures unchanged, we get rid of those entry points and the
compat_time types by renaming them to something that makes more sense
on 32-bit architectures (which don't have a compat mode otherwise),
and then share the entry points under the new name with the 64-bit
architectures that use them for implementing the compatibility.
The following types and interfaces are renamed here, and moved
from linux/compat_time.h to linux/time32.h:
old new
--- ---
compat_time_t old_time32_t
struct compat_timeval struct old_timeval32
struct compat_timespec struct old_timespec32
struct compat_itimerspec struct old_itimerspec32
ns_to_compat_timeval() ns_to_old_timeval32()
get_compat_itimerspec64() get_old_itimerspec32()
put_compat_itimerspec64() put_old_itimerspec32()
compat_get_timespec64() get_old_timespec32()
compat_put_timespec64() put_old_timespec32()
As we already have aliases in place, this patch addresses only the
instances that are relevant to the system call interface in particular,
not those that occur in device drivers and other modules. Those
will get handled separately, while providing the 64-bit version
of the respective interfaces.
I'm not renaming the timex, rusage and itimerval structures, as we are
still debating what the new interface will look like, and whether we
will need a replacement at all.
This also doesn't change the names of the syscall entry points, which can
be done more easily when we actually switch over the 32-bit architectures
to use them, at that point we need to change COMPAT_SYSCALL_DEFINEx to
SYSCALL_DEFINEx with a new name, e.g. with a _time32 suffix.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Link: https://lore.kernel.org/lkml/20180705222110.GA5698@infradead.org/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Three ipc syscalls (mq_timedsend, mq_timedreceive and and semtimedop)
take a timespec argument. After we move 32-bit architectures over to
useing 64-bit time_t based syscalls, we need seperate entry points for
the old 32-bit based interfaces.
This changes the #ifdef guards for the existing 32-bit compat syscalls
to check for CONFIG_COMPAT_32BIT_TIME instead, which will then be
enabled on all existing 32-bit architectures.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This is a preparatation for changing over __kernel_timespec to 64-bit
times, which involves assigning new system call numbers for mq_timedsend(),
mq_timedreceive() and semtimedop() for compatibility with future y2038
proof user space.
The existing ABIs will remain available through compat code.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This reverts commit 36735a6a2b.
Aleksa Sarai <asarai@suse.de> writes:
> [REGRESSION v4.16-rc6] [PATCH] mqueue: forbid unprivileged user access to internal mount
>
> Felix reported weird behaviour on 4.16.0-rc6 with regards to mqueue[1],
> which was introduced by 36735a6a2b ("mqueue: switch to on-demand
> creation of internal mount").
>
> Basically, the reproducer boils down to being able to mount mqueue if
> you create a new user namespace, even if you don't unshare the IPC
> namespace.
>
> Previously this was not possible, and you would get an -EPERM. The mount
> is the *host* mqueue mount, which is being cached and just returned from
> mqueue_mount(). To be honest, I'm not sure if this is safe or not (or if
> it was intentional -- since I'm not familiar with mqueue).
>
> To me it looks like there is a missing permission check. I've included a
> patch below that I've compile-tested, and should block the above case.
> Can someone please tell me if I'm missing something? Is this actually
> safe?
>
> [1]: https://github.com/docker/docker/issues/36674
The issue is a lot deeper than a missing permission check. sb->s_user_ns
was is improperly set as well. So in addition to the filesystem being
mounted when it should not be mounted, so things are not allow that should
be.
We are practically to the release of 4.16 and there is no agreement between
Al Viro and myself on what the code should looks like to fix things properly.
So revert the code to what it was before so that we can take our time
and discuss this properly.
Fixes: 36735a6a2b ("mqueue: switch to on-demand creation of internal mount")
Reported-by: Felix Abecassis <fabecassis@nvidia.com>
Reported-by: Aleksa Sarai <asarai@suse.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previous behavior added tasks to the work queue using the static_prio
value instead of the dynamic priority value in prio. This caused RT tasks
to be added to the work queue in a FIFO manner rather than by priority.
Normal tasks were handled by priority.
This fix utilizes the dynamic priority of the task to ensure that both RT
and normal tasks are added to the work queue in priority order. Utilizing
the dynamic priority (prio) rather than the base priority (normal_prio)
was chosen to ensure that if a task had a boosted priority when it was
added to the work queue, it would be woken sooner to to ensure that it
releases any other locks it may be holding in a more timely manner. It is
understood that the task could have a lower priority when it wakes than
when it was added to the queue in this (unlikely) case.
Link: http://lkml.kernel.org/r/1513006652-7014-1-git-send-email-jhaws@sdl.usu.edu
Signed-off-by: Jonathan Haws <jhaws@sdl.usu.edu>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull mqueue/bpf vfs cleanups from Al Viro:
"mqueue and bpf go through rather painful and similar contortions to
create objects in their dentry trees. Provide a primitive for doing
that without abusing ->mknod(), switch bpf and mqueue to it.
Another mqueue-related thing that has ended up in that branch is
on-demand creation of internal mount (based upon the work of Giuseppe
Scrivano)"
* 'work.mqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
mqueue: switch to on-demand creation of internal mount
tidy do_mq_open() up a bit
mqueue: clean prepare_open() up
do_mq_open(): move all work prior to dentry_open() into a helper
mqueue: fold mq_attr_ok() into mqueue_get_inode()
move dentry_open() calls up into do_mq_open()
mqueue: switch to vfs_mkobj(), quit abusing ->d_fsdata
bpf_obj_do_pin(): switch to vfs_mkobj(), quit abusing ->mknod()
new primitive: vfs_mkobj()
Pull poll annotations from Al Viro:
"This introduces a __bitwise type for POLL### bitmap, and propagates
the annotations through the tree. Most of that stuff is as simple as
'make ->poll() instances return __poll_t and do the same to local
variables used to hold the future return value'.
Some of the obvious brainos found in process are fixed (e.g. POLLIN
misspelled as POLL_IN). At that point the amount of sparse warnings is
low and most of them are for genuine bugs - e.g. ->poll() instance
deciding to return -EINVAL instead of a bitmap. I hadn't touched those
in this series - it's large enough as it is.
Another problem it has caught was eventpoll() ABI mess; select.c and
eventpoll.c assumed that corresponding POLL### and EPOLL### were
equal. That's true for some, but not all of them - EPOLL### are
arch-independent, but POLL### are not.
The last commit in this series separates userland POLL### values from
the (now arch-independent) kernel-side ones, converting between them
in the few places where they are copied to/from userland. AFAICS, this
is the least disruptive fix preserving poll(2) ABI and making epoll()
work on all architectures.
As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
it will trigger only on what would've triggered EPOLLWRBAND on other
architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
at all on sparc. With this patch they should work consistently on all
architectures"
* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
make kernel-side POLL... arch-independent
eventpoll: no need to mask the result of epi_item_poll() again
eventpoll: constify struct epoll_event pointers
debugging printk in sg_poll() uses %x to print POLL... bitmap
annotate poll(2) guts
9p: untangle ->poll() mess
->si_band gets POLL... bitmap stored into a user-visible long field
ring_buffer_poll_wait() return value used as return value of ->poll()
the rest of drivers/*: annotate ->poll() instances
media: annotate ->poll() instances
fs: annotate ->poll() instances
ipc, kernel, mm: annotate ->poll() instances
net: annotate ->poll() instances
apparmor: annotate ->poll() instances
tomoyo: annotate ->poll() instances
sound: annotate ->poll() instances
acpi: annotate ->poll() instances
crypto: annotate ->poll() instances
block: annotate ->poll() instances
x86: annotate ->poll() instances
...
Call clear_siginfo to ensure stack allocated siginfos are fully
initialized before being passed to the signal sending functions.
This ensures that if there is the kind of confusion documented by
TRAP_FIXME, FPE_FIXME, or BUS_FIXME the kernel won't send unitialized
data to userspace when the kernel generates a signal with SI_USER but
the copy to userspace assumes it is a different kind of signal, and
different fields are initialized.
This also prepares the way for turning copy_siginfo_to_user
into a copy_to_user, by removing the need in many cases to perform
a field by field copy simply to skip the uninitialized fields.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Instead of doing that upon each ipcns creation, we do that the first
time mq_open(2) or mqueue mount is done in an ipcns. What's more,
doing that allows to get rid of mount_ns() use - we can go with
considerably cheaper mount_nodev(), avoiding the loop over all
mqueue superblock instances; ipcns->mq_mnt is used to locate preexisting
instance in O(1) time instead of O(instances) mount_ns() would've
cost us.
Based upon the version by Giuseppe Scrivano <gscrivan@redhat.com>; I've
added handling of userland mqueue mounts (original had been broken in
that area) and added a switch to mount_nodev().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is a pure automated search-and-replace of the internal kernel
superblock flags.
The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.
Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.
The script to do this was:
# places to look in; re security/*: it generally should *not* be
# touched (that stuff parses mount(2) arguments directly), but
# there are two places where we really deal with superblock flags.
FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
include/linux/fs.h include/uapi/linux/bfs_fs.h \
security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
# the list of MS_... constants
SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
ACTIVE NOUSER"
SED_PROG=
for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done
# we want files that contain at least one of MS_...,
# with fs/namespace.c and fs/pnode.c excluded.
L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')
for f in $L; do sed -i $f $SED_PROG; done
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
struct timespec is not y2038 safe. Replace
all uses of timespec by y2038 safe struct timespec64.
Even though timespec is used here to represent timeouts,
replace these with timespec64 so that it facilitates
in verification by creating a y2038 safe kernel image
that is free of timespec.
The syscall interfaces themselves are not changed as part
of the patch. They will be part of a different series.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The retry logic for netlink_attachskb() inside sys_mq_notify()
is nasty and vulnerable:
1) The sock refcnt is already released when retry is needed
2) The fd is controllable by user-space because we already
release the file refcnt
so we when retry but the fd has been just closed by user-space
during this small window, we end up calling netlink_detachskb()
on the error path which releases the sock again, later when
the user-space closes this socket a use-after-free could be
triggered.
Setting 'sock' to NULL here should be sufficient to fix it.
Reported-by: GeneBlue <geneblue.mail@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
... and stop messing with compat_alloc_user_space() and friends
[braino fix from Colin King folded in]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We are going to split <linux/sched/user.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/user.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/wake_q.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/wake_q.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently the wake_q data structure is defined by the WAKE_Q() macro.
This macro, however, looks like a function doing something as "wake" is
a verb. Even checkpatch.pl was confused as it reported warnings like
WARNING: Missing a blank line after declarations
#548: FILE: kernel/futex.c:3665:
+ int ret;
+ WAKE_Q(wake_q);
This patch renames the WAKE_Q() macro to DEFINE_WAKE_Q() which clarifies
what the macro is doing and eliminates the checkpatch.pl warnings.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1479401198-1765-1-git-send-email-longman@redhat.com
[ Resolved conflict and added missing rename. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.
CURRENT_TIME is also not y2038 safe.
This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.
Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Introduce a function may_open_dev that tests MNT_NODEV and a new
superblock flab SB_I_NODEV. Use this new function in all of the
places where MNT_NODEV was previously tested.
Add the new SB_I_NODEV s_iflag to proc, sysfs, and mqueuefs as those
filesystems should never support device nodes, and a simple superblock
flags makes that very hard to get wrong. With SB_I_NODEV set if any
device nodes somehow manage to show up on on a filesystem those
device nodes will be unopenable.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Set SB_I_NOEXEC on mqueuefs to ensure small implementation mistakes
do not result in executable on mqueuefs by accident.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Today what is normally called data (the mount options) is not passed
to fill_super through mount_ns.
Pass the mount options and the namespace separately to mount_ns so
that filesystems such as proc that have mount options, can use
mount_ns.
Pass the user namespace to mount_ns so that the standard permission
check that verifies the mounter has permissions over the namespace can
be performed in mount_ns instead of in each filesystems .mount method.
Thus removing the duplication between mqueuefs and proc in terms of
permission checks. The extra permission check does not currently
affect the rpc_pipefs filesystem and the nfsd filesystem as those
filesystems do not currently allow unprivileged mounts. Without
unpvileged mounts it is guaranteed that the caller has already passed
capable(CAP_SYS_ADMIN) which guarantees extra permission check will
pass.
Update rpc_pipefs and the nfsd filesystem to ensure that the network
namespace reference is always taken in fill_super and always put in kill_sb
so that the logic is simpler and so that errors originating inside of
fill_super do not cause a network namespace leak.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg. For the list, see below:
- threadinfo
- task_struct
- task_delay_info
- pid
- cred
- mm_struct
- vm_area_struct and vm_region (nommu)
- anon_vma and anon_vma_chain
- signal_struct
- sighand_struct
- fs_struct
- files_struct
- fdtable and fdtable->full_fds_bits
- dentry and external_name
- inode for all filesystems. This is the most tedious part, because
most filesystems overwrite the alloc_inode method.
The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds. Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
